Re: Corona Bottle Capacitance and twin coils...

["Tesla list" <tesla@xxxxxxxxxx>]

Original poster: Gregory Hunter <tesla_39560@xxxxxxxxx>

>      Could someone who knows please post the
> capacitance of one (or
> ten, or whatever) Corona bottles, filled with salt
> water internally
> and externally to within 2 inches of the top? I know
> this has been
> discussed but I can't find it in the archives
> (probably due to pilot error).

A 12 oz beer or wine cooler bottle is good for
750-900pF. A six pack is good for 5nF. A 12 pack is OK
for about 10nF.

>
>      Right now I have qty 12 in parallel, but I do
> not have anything
> like a capacitor meter. (I am building Terry's

You don't need a meter. The above figure was widely
circulated on the WWW before I came along. I have
verified it myself with several different brands of
beer bottle using two different brands of cap meter. I
am satisfied that 5nF per six pack is close enough for
hobby coiling.

> oscillator to help
> find resonant frequency, but am stuck on a few
> parts; Radio Shacks,
> etc, are few and far between around here).
>
>      Second question: Does it really matter if I
> wrap the Corona
> bottles in aluminum foil prior to mostly submerging
> them in the salt
> water? If it makes a big difference I'll do it, but
> right now the
> water in there is as salty as possible.

If you plan to wrap the bottles in foil, you don't
need the salt bath. If you plan to use a salt bath,
you don't need the foil. The salt bath will give
slightly higher capacitance. The foil wrap is lighter,
neater, and dryer. Performance is about the same (not
too impressive) either way. Take your pick.

>
>     ( If a reference is needed for the size of a cap
> needed, I'm
> running a 12kv, 60 ma NST, ~~ 10 turn primary, ~~500
> turn secondary.)

Resonant value for a 12/60 at 60Hz is 13.3nF. LTR
value for a static gap coil is about 20nF.

>      Dave Small

Cheers,




Gregory R. Hunter

http:\\hot-streamer.com/greg